On This Day . . .

Square Peg in Round Hole

April 11, 1970: Apollo 13 Launched to the Moon

On April 11, 1970 one of our most challenging space missions began. The third lunar landing mission is successfully launched from Cape Canaveral carrying astronauts James A. Lovell, John L. Swigert, and Fred W. Haise. On April 13 an oxygen tank exploded and the new mission objective was to get the Apollo 13 crew home alive.

Oxygen tank 2 had blown up disabling the normal supply of oxygen, electricity, light and water. Lovell reported to mission control: “Houston, we’ve had a problem here”. At this point the crew didn’t know what had happened. They heard a “bang” and saw a gas venting from the spacecraft.

The CM (command module) lost pressure, and the fuel cells died an hour after the explosion so they decided to move into the LM (lunar module) which had sufficient oxygen. The LM became their lifeboat, but could not be used to come back to earth. The CM was shut down but would have to be brought back to life in order to bring the astronauts back alive.

Damaged Spacecraft

Damaged Spacecraft

The LM could only support two people for 45 hours. If the crew were to make it back to earth alive the LM would have to support three men for at least 90 hours and navigate more than 200,000 miles of space. No one knew if it could be done.

The crew went on one-fifth water rations and had to endure temps that hovered a few degrees about freezing. Removal of carbon dioxide was also a huge problem. The square lithium hydroxide canisters from the CM were not compatible with the round openings in the LM’s system. Mission control had to build an impromptu adapter out of materials known to be onboard, including the always handy duct tape.

Navigation was also a primary problem, as the LM didn’t have the sophisticated navigational system of the dead CM. The astronauts had to fly by the seat of their pants working out complicated changes in propulsion with mission control to get the spacecraft in the right direction to bring them home.

The crew of Apollo 13 photographed the Moon from their Lunar Module “life boat” as they passed by it

On April 14, Apollo 13 swung around the moon and Lovell talked with mission control about the most difficult maneuver yet, a five minute burn that would give the LM enough speed to return the crew home before its energy ran out. Two hours after rounding the far side of the moon, the crew, using the sun as an alignment tool, fired the LM’s small descent engine. The procedure was a success and Apollo was on its way home.

For the next three days, Lovell, Haise, and Swigert huddled in the freezing lunar module – Haise developed a case of the flu. Mission control spent its time frantically trying to develop a procedure that would allow the astronauts to restart the CM for reentry. A last minute navigational correction was made on April 17, this time using the Earth as an alignment guide. The depressurized CM was successfully powered up after a long cold sleep and the heavily damaged service module was shed one hour before reentry.

The spacecraft reentered Earth’s atmosphere just before 1 p.m. Mission control was worried that the CM’s heat shields were damaged in the explosion, which would burn the astronauts alive. There were four tense minutes of radio silence before Apollo 13’s parachutes were spotted and an “OK” was heard from Lovell. The spacecraft safely splashed down in the Pacific.